Note: The Illinois Department of Revenue does not require third party software vendors to support all forms in their software product. Software vendors are allowed to develop their tax preparation software based on the needs of their clients. Check each product or service for details on services and associated costs.

Developers

Substitute Forms DevelopersIf you produce, or intend to produce, your own version of the official tax forms, you can find information here about our technical specifications, enrollment, and testing requirements.